The invention relates to a data carrier which can be operated in a contact-bound mode and in a contactless mode and which includes the means specified hereinafter, namely contact-bound interface means via which data can be received in the contact-bound mode and which include contact-bound data output means for supplying data received in the contact-bound mode, and contactless interface means via which data can be received in the contactless mode and which include contactless data output means for supplying data received in the contactless mode, and data processing means which include data input means for receiving data received in the contact-bound mode and received in the contactless mode and by which the data received in the contact-bound mode and received in the contactless mode can be processed, and data transfer means which include first data input means and second data input means as well as data output means, of which the first data input means are connected to the contact-bound data output means of the contact-bound interface means, and of which the second data input means are connected to the contactless data output means of the contactless interface means, and of which the data output means are connected to the data input means of the data processing means, and which are constructed to transfer data received in the contact-bound mode and applied to their first data input means, and to transfer data received in the contactless mode and applied to the data processing means via their data output means, and to inhibit a transfer of received data from one of their data input means to the other one of the data input means.
The invention further relates to a circuit for a data carrier, which circuit can be operated in a contact-bound mode and in a contactless mode and which includes the means specified hereinafter, namely contact-bound interface means via which data can be received in the contact-bound mode and which include contact-bound data output means for supplying data received in the contact-bound mode, and contactless interface means via which data can be received in the contactless mode and which include contactless data output means for supplying data received in the contactless mode, and data processing means which include data input means for receiving data received in the contact-bound mode and received in the contactless mode and by which the data received in the contact-bound mode and received in the contactless mode can be processed, and data transfer means which include first data input means and second data input means as well as data output means, of which the first data input means are connected to the contact-bound data output means of the contact-bound interface means, and of which the second data input means are connected to the contactless data output means of the contactless interface means, and of which the data output means are connected to the data input means of the data processing means, and which are constructed to transfer data received in the contact-bound mode and applied to their first data input means, and to transfer data received in the contactless mode and applied to the data processing means via their data output means, and to inhibit a transfer of received data from one of their data input means to the other one of the data input means.
Such a data carrier of the type defined in the first paragraph and such a circuit of the type defined in the second paragraph are known, for example from the document U.S. Pat. No. 5,206,495.
In the known data carrier and the known circuit the data transfer means have a construction by means of which a change-over between the contact-bound interface means and the contactless interface means is possible. Said document states that the data transfer means are constituted by a so-called multiplexer. As described in said document in column 3, lines 7 to 10 and in column 4, lines 3 to 5, such data transfer means enable either data supplied by the contact-bound interface means or data supplied by the contactless interface means to be transferred to the data processing means. Such known data transfer means, which preferably take the form of a multiplexer, are of a comparatively intricate circuit design, because such a multiplexer normally or usually comprises at least two AND gates, an inverter and an OR gate. Moreover, in the case of such data transfer means constructed as a change-over switch, it is necessary that these data transfer means have a control input arranged to receive a control signal or control information for controlling the change-over, separate control signal generating means or control information generating means being needed for the generation of this control signal or the control information. Thus, everything considered, the construction of a data carrier or a circuit for such a data carrier as known from the document U.S. Pat. No. 5,206,495 requires a comparatively high circuit complexity, which even in the case of implementation in integrated circuit technology is to be regarded as rather unfavorable.